'\" et
.TH SHIFT "1P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
shift
\(em shift positional parameters
.SH SYNOPSIS
.LP
.nf
shift \fB[\fIn\fB]\fR
.fi
.SH DESCRIPTION
The positional parameters shall be shifted. Positional parameter 1
shall be assigned the value of parameter (1+\fIn\fP), parameter 2 shall
be assigned the value of parameter (2+\fIn\fP), and so on. The
parameters represented by the numbers
.BR \(dq$#\(dq 
down to
.BR \(dq$#-n+1\(dq 
shall be unset, and the parameter
.BR '#' 
is updated to reflect the new number of positional parameters.
.P
The value
.IR n
shall be an unsigned decimal integer less than or equal to the value of
the special parameter
.BR '#' .
If
.IR n
is not given, it shall be assumed to be 1. If
.IR n
is 0, the positional and special parameters are not changed.
.SH OPTIONS
None.
.SH OPERANDS
See the DESCRIPTION.
.SH STDIN
Not used.
.SH "INPUT FILES"
None.
.SH "ENVIRONMENT VARIABLES"
None.
.SH "ASYNCHRONOUS EVENTS"
Default.
.SH STDOUT
Not used.
.SH STDERR
The standard error shall be used only for diagnostic messages.
.SH "OUTPUT FILES"
None.
.SH "EXTENDED DESCRIPTION"
None.
.SH "EXIT STATUS"
If the
.IR n
operand is invalid or is greater than
.BR \(dq$#\(dq ,
this may be considered a syntax error and a non-interactive shell may
exit; if the shell does not exit in this case, a non-zero exit status
shall be returned. Otherwise, zero shall be returned.
.SH "CONSEQUENCES OF ERRORS"
Default.
.LP
.IR "The following sections are informative."
.SH "APPLICATION USAGE"
None.
.SH EXAMPLES
.LP
.nf
\fB$\fR set a b c d e
\fB$\fR shift 2
\fB$\fR echo $*
\fBc d e\fR
.fi
.SH "RATIONALE"
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "Section 2.14" ", " "Special Built-In Utilities"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
